The former Mexican President is not a fan of The Donald.

Former Mexican President Felipe Calderon spoke with CNBC in an interview published this weekend and had nothing but disdain for Donald Trump, and especially for the presidential candidate's plan to build a border wall paid for by Mexico.

"Mexican people, we are not going to pay any single cent for such a stupid wall! And it's going to be completely useless," Calderon said.

"The first loser of such a policy would be the United States," he said. "If this guy pretends that closing the borders to anywhere either for trade (or) for people is going to provide prosperity to the United States, he is completely crazy."

Calderon offered a whole slew of other insults for the Donald, calling him uniformed and expressing disbelief that the United States could even take him seriously as a candidate for President.

He also told CNBC that the perception of a flow of illegals into the United States for work is not true:

U.S. census data for the same period show an estimated 870,000 Mexican nationals left Mexico to come to the U.S., a smaller number than the flow of families from the U.S. to Mexico.

Calderon said that children studying in Mexican schools and universities no longer wanted to go the U.S. as they had opportunities closer to home with around 4 percent unemployment, although he conceded that there were still "bad salaries" in Mexico.

"They don't want to go, they can work for a motor company (that's) not in Detroit, I am sorry to say. They are working for a motor company in Hermosillo and Toluca, so Mazda is coming to Mexico, Honda is coming to Mexico. Those kids have jobs in that industry in Mexico."

Like Calderon, this weekend Trump noted (if inadvertently) that corporations and businesses have moved to Mexico not just for cheaper labor, but to escape an oppressive tax environment here, during which statement he made an amazing remark that took attention away from the fact that he was stating that there are jobs in Mexico.

One can argue the merits or justice of Donald Trump's plan, but when it comes to what Mexico is actually going to do, or where they will spend their treasury, it's more likely that the former President of that country has a more realistic grasp of that than Trump does.